<template>
  <div id="home">
    <nav-bar class="home-nav">
      <div slot="center">购物街</div>
    </nav-bar>
    <tab-control
      :title="['流行' , '新款' , '精选']"
      @tabClick="tabClick"
      ref="tabControl1"
      class="tab-control"
      v-show="isTabFixed"
    ></tab-control>
    <scroll
      class="content"
      ref="scroll"
      :probe-type="3"
      @scroll="contentScroll"
      :pull-up-load="true"
      @pullingUp = "loadMore"
    >
      <home-swiper :banners="banners" @swiperImageLoad = 'swiperImageLoad'></home-swiper>
      <recommend-view :recommends="recommends"></recommend-view>
      <feature-view></feature-view>
      <tab-control
        :title="['流行' , '新款' , '精选']"
        @tabClick="tabClick"
        ref="tabControl2"
      ></tab-control>
      <goods-list :goods="showGoods"></goods-list>
    </scroll>
    <!--监听原生组件必须添加native-->
    <back-top @click.native="backClick" v-show="isShowBackTop"></back-top>
  </div>
</template>

<script>
import HomeSwiper from "./childComps/HomeSwiper";
import RecommendView from "./childComps/RecommendView";
import FeatureView from "./childComps/FeatureView";

import NavBar from 'components/common/navbar/NavBar';
import TabControl from "components/content/tabControl/TabControl";
import GoodsList from "components/content/goods/GoodsList";
import Scroll from "components/common/scroll/Scroll";
import BackTop from "components/content/backTop/BackTop";

import {getHomeMultidate, getHomeGoods} from "network/home";
// import {debounce} from "components/common/utils";
import {itemListenerMixin} from "common/mixin";

export default {
  name: "Home",
  components: {
    NavBar,
    HomeSwiper,
    RecommendView,
    FeatureView,
    TabControl,
    GoodsList,
    Scroll,
    BackTop
  },
  //混入导入
  mixins: [itemListenerMixin],
  data() {
    return {
      banners: [],
      recommends: [],
      goods: {
        'pop': {page: 0, list: []},
        'new': {page: 0, list: []},
        'sell': {page: 0, list: []}
      },
      currentType: 'pop',
      isShowBackTop: false,
      tabOffsetTop: 0,
      isTabFixed: false,
      saveY: 0,
    }
  },
  computed: {
    showGoods() {
      return this.goods[this.currentType].list
    }
  },
  activated() {
    this.$refs.scroll.scrollTo(0 , this.saveY , 0);
    // 滚动到原来的位置后最后做一次刷新， 防止未知的错误
    this.$refs.scroll.refresh();
  },
  deactivated() {
    // 保存Y值
    this.saveY = this.$refs.scroll.getScrollY();
    // 取消全局事件监听
    this.$bus.$off('itemImgLoad', this.itemImgListener)
  },
  created() {
    // 1 请求多个数据，此操作为异步操作
    this.getHomeMultidate();
    //请求home多个数据
    this.getHomeGoods('pop');
    this.getHomeGoods('new');
    this.getHomeGoods('sell');

  },
  mounted() {
/*    // 图片加载完成事件监听
    const  refresh = debounce(this.$refs.scroll.refresh , 500);
    // 监听goodsListItem 是否加载完成
    this.$bus.$on('itemImageLoad', () => {
      // console.log("------------");
      refresh();
      // this.$refs.scroll.refresh()
    })*/
  },
  methods: {
    /**
     * 事件监听相关方法
     */
    tabClick(index) {
      // console.log(index);
      switch (index) {
        case 0:
          this.currentType = 'pop';
          break;
        case  1:
          this.currentType = 'new';
          break;
        case  2:
          this.currentType = 'sell';
          break;
      }
      this.$refs.tabControl1.currentIndex = index;
      this.$refs.tabControl2.currentIndex = index;
    },
    backClick() {
      // console.log('点击');
      // 第一个scroll表示拿到ref里面的值，第二个scroll表示scroll组件里面的scroll属性
      // this.$refs.scroll.scroll.scrollTo(0 , 0 , 1000);
      // 直接调用scroll里面的scrollTo方法
      this.$refs.scroll.scrollTo(0, 0, 1000);
    },
    contentScroll(position) {
      // 判断backTop是否显示
      this.isShowBackTop = (-position.y) > 1000
      // 决定tabControl是否吸顶，定位模式改成固定定位
      this.isTabFixed = (-position.y) > this.tabOffsetTop
    },
    loadMore() {
      // console.log('加载更多');
      this.getHomeGoods(this.currentType)
    },
    swiperImageLoad() {
      // 获取tabControl的offsetTop
      // 所有组件都有一个属性$el,用于获取组件中的元素,在mounted中获取的值因为图片加载有事件间隔，值是不确定的，轮播图片加载完毕后再监听即可拿到真实的值
      this.tabOffsetTop = this.$refs.tabControl2.$el.offsetTop;
    },
    /**
     * 网络请求相关方法
     */
    getHomeMultidate() {
      getHomeMultidate().then(res => {
        // console.log(res.data);
        //将数据分别存储起来
        this.banners = res.data.banner.list;
        this.recommends = res.data.recommend.list;
      })
    },
    getHomeGoods(type) {
      // 动态获取显示的页数
      const page = this.goods[type].page + 1;
      getHomeGoods(type, page).then(res => {
        // console.log(res)
        // 将每次请求到的数据动态添加进去
        this.goods[type].list.push(...res.data.list);
        this.goods[type].page += 1;
        // 完成上拉加载更多，保证上拉加载更多会多次实现
        this.$refs.scroll.finishPullUp()
      })
    },
  }
}
</script>

<style scoped>
#home {
  position: relative;
  /*padding-top: 44px;*/
  height: 100vh;
}

.home-nav {
  /*设置浏览器原生滚动是需要此设置*/
  /*position: fixed;*/
  /*top: 0;*/
  /*right: 0;*/
  /*left: 0;*/
  /*z-index: 9999;*/
  background-color: var(--color-tint);
  color: #fff;
}

.tab-control {
  position: relative;
  z-index: 999;

}

.content {
  position: absolute;
  height: calc(100% - 93px);
  overflow: hidden;
  top: 44px;
  bottom: 49px;
  left: 0;
  right: 0;
}
</style>
